Controllable liquid conveying assembly



y 1968 H. JAUN ETAL 3,385,224

CONTROLLABLE LIQUID CONVEYING ASSEMBLY Filed March 23, 1966 3Sheets-Sheet 1 i 1 2s 10 I 33 i fjq 15 63 I I U Inventors: HANS MOSERHERMANN IA UN by 710v? I Attorney May 28, 1968 H. JAUN ETAL CONTROLLABLELIQUID CONVEYING ASSEMBLY Filed March 23, 1966 3 Sheets-Sheet 2Inventors:

HANS MOSER HERMANN IA UN M a L ttorney y 8, 1968 H. .JAUN ETAL 3,385,224

CONTR OLLABLE LIQUID CONVEYING ASSEMBLY Filed March 23, 1966 3Sheets-Sheet 3 Inventors: HANS MOSER HERMANN IAUN by W M7,

Attorney United States Patent 3,385,224 CONTROLLABLE LIQUID CONVEYINGASSEMBLY Hermann .Iaun, Rcgensdorf, Zurich, and Hans Moser, Zurich,Switzerland, assignors to Micro-Electric AG, and Hans Moser Filed Mar.23, 1966, Ser. No. 536,692 Claims priority, application Germany, Mar.25, 1965, M 64,655 13 Claims. (Cl. 103-97) ABST'RAtIT OF THE DISCLOSUREA pump has a control element mounted within its pump housing. On thiscontrol element is mounted sealing means to seal the inlet and theoutlet of the housing. The control element furthermore has passages fordirecting fluid within the housing to and from the pump impeller. Thecontrol element is adjustable between a position in which the inlet andoutlet openings are sealed closed and a position in which these openingsare in communication with the pump impeller.

The invention relates to a controllable liquid conveying assembly havingan axially divisible housing whose component parts are designated in thefollowing as pump housing and motor block housing, as well as a controlelement actuatable externally for controlling the conveying liquidradially flowing to and discharging from the pump housing.

The objects of the invention are:

To provide a liquid conveying assembly which permits the conveyance ofliquids having a relatively high content of foreign bodies, in anunfiltered state, or which can be placed in operation again withoutdifliculty even after long intervals of inoperativeness, such as, forexample, a pump for hot water heaters with forced cycle.

To provide an assembly of the type mentioned having means to freerepidly critical parts of the assembly from foreign bodies and, ifrequired, to quickly exchange those parts.

To provide a controllable liquid conveying asembly of theabove-described type wherein the control element is provided withsealing elements permitting the sealing of the pump housing in aliquid-tight manner, and wherein the pump impeller is combinedstructurally with the rotor of an axial electric motor, without the useof glands or stuffing boxes.

To provide an assembly of the type mentioned including means separatingthe pump housing from the conveying liquid cycle and to reach theaxially divisible housing after the control element is brought into itsclosed position, whereby after opening of the assembly it is possiblesimply to disassemble in dry state the stator of the axial motor, andalso the structural unit formed by the pump impeller and the rotor ofthe motor and without difficulty to exchange it or to clean it, and thento reassemble it.

To provide the assembly of the invention with liquid inlet and outletopenings of the pump housing enclosed, in the closed position of thecontrol element, preferably by one sealing element positioned in asealing manner between the housing and the control element.

To provide the assembly of the invention with a particularly simple,compact structure by positioning the control element rotatably andcoaxially to the pump motor axis and by giving this control element anouter surface movable as a seal in front of the liquid inlet and outletopenings.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same 3,385,224 Patented May 28, 1968becomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingin which like reference numerals designate like parts throughout thefigures thereof and wherein:

FIGURE 1 is a partially cross-sectioned, longitudinal view of acontrollable liquid conveying assembly according to the invention.

FIGURE 2 illustrates, on a larger scale, a partial view of thearrangement of FIGURE 1 showing in detail the construction of theconical bearing for the unit formed by the motor rotor and the pumpimpeller.

FIGURE 3 is a view of the pump housing and the control element shown inthe direction of arrow A of FIGURE 1, after the motor block housing hasbeen removed, together with the unit formed by the motor rotor and thepump impeller, the control element being illustrated in the closedposition.

FIGURE 4 is a view of the control element in the direction of arrow B ofFIGURE 3.

FIGURE 5 shows, on a larger scale, a partial cross section through amodified embodiment of the invention wherein the control element isaxially displaceable and connectible with the pump impeller; and

FIGURE 6 shows a section along line VIVI of FIG- URE 5.

The liquid conveying assembly of FIGURES 14 is provided with an axiallydivisible housing having a pump housing 1 and a motor block housing 2.

The stator of the axial motor mounted in the motor block housing isprovided with an annular magnetic iron core 3, and excitation windings 4supplied with current from the mains. A screw bolt 7 is threadedlyinserted into an axial bore 5 of a central boss 6 of the motor blockhousing 2. A membrane 8 seals the motor block housing on the side facingthe pump housing 1, in a fluid-tight manner; a seal 10 inserted in anannular body 9 sealingly engages the central, smooth section 11 of thescrew bolt 7 and the membrane '8. An insulating cast mass 12, forexample of synthetic resin or silicone rubber, filled in after themembrane 8 has been mounted at the motor block housing, supports themembrane against the fluid pressure of the rotor chamber andsimultaneously protects the stator windings.

An axle 15 is threaded onto the end of the screw bolt 7 facing away fromthe boss 6 of the motor block housing. The axle carries a shaft box 16on the side facing the motor block housing on which the rotor of theaxial motor, having an annular magnetic iron core 17 and a squirrel cagewinding 18, is positioned. The pump impeller 19 is fixedly connectedwith the rotor 17, 18 of the axial motor, for example by a threadedconnection. The impeller 19 is a centrifugal impeller and has open vanes20. The boss 21 of the impeller carries a bearing ring 22, seen in FIG.2, which forms a conical bearing together with a cone-shaped bearingpart 23 inserted into the end of the axle, facing away from the motorblock housing. The bearing ring 22 and the bearing part 23 are made ofhard metal or other material resistant to wear and tear.

In operation, the magnetic forces effective between the stator 3, 4 andthe rotor 17, 18 of the axial motor attempt to pull the rotor againstthe stator. These forces are absorbed by the conical bearing 22, 23effective as an axial bearing, while the axle, together with the shaftbox 16 rotatably mounted thereon, forms a radial bearing for thestructural unit formed by the motor rotor 17, 18 and the pump impeller19.

An annular flange 25 of the motor block housing encompasses the open endof the pump housing facing the motor block housing. Screws 26 whichextend through radial flanged portions of the motor block housing andwhich are threaded into threaded bores 27 of lugs 28 of 3 the pumphousing as seen in FIG. 3, hold the housing parts 1, 2 together in adetachable fashion. In this connection, a sealing ring 29 insertedbetween the front edge of the pump housing and the membrane establishesa fluidtight connection of the two housing portions 1, 2.

The pump housing has radial connecting studs 32, 33 which oppose eachother diametrically. In the front wall 34 of the pump housing, facingaway from the motor block housing is rotatably mounted the boss 35 ofthe control element 36. A handwheel 39 having the shape of a disk andbeing provided with grip-type teeth 38 is mounted by screws 37 at theend of the boss 35 extending beyond the front wall 34 to the outside. Acup spring 40 pushed onto the boss abuts against the outer surface ofthe front wall 34 and the front edge of the boss 41 of the handwheel 39.The spring 40 attempts to press the control element 36 against the frontwall 34 so that the shoulder 42 of the control element engages thesealing ring 43 and the inner surface of the front wall 34. A sealingring 44 held in an annular groove in the boss 35 presses against thewall of the bore of the front wall 34 receiving the boss 35. The boss 35and the handwheel 39 have central bores which are in alignment with oneanother. A locking screw 45 with a sealing ring 46 is passed through thecentral bore of the handwheel 39 and is threaded into the central boreof the boss 35.

The control element 36 has a cylindrical outer surface 43 slidinglyfitting into the bore of the pump housing. Flat, circular recesses 56,5'1 of the outer surface 48, which oppose each other diametrically,serve for receiving sealing rings 52 which encompass in a sealing mannerthe bores of the connecting lugs 32, 33 in the closed position of thecontrol element 36 illustrated in FIGURES 1 and 3, and thus separate thepump housing 1 in a fluidtight manner from the liquid cycle connected tothe studs 32, 33.

As seen from FIGS. 3 and 4, the outer surface 48 of the control elementis provided with a stepped liquid inlet opening 53 and the controlelement on the side of the impeller is provided with two tongue-shapedguide flanks 54, 55. The guide flanks 54, 55 form an acute angle withthe tangent on the circumference of the control element 36, this anglebeing preferably between and 75. The mutual distance of the guide flanks54, 55 corresponds, at the periphery of the control element 36,approximately to the width of the opening of the connecting pipes 32, 33in the direction of their circumference.

By turning the control element 36 from the closed position according toFIGURE 3 in counter-clockwise direction, there is first brought intocongruence with the bore of the connecting pipe 32 the smallercross-sectional area 64, and then the larger cross-sectional area of theinlet opening 53 of the control element. Thus, progressively largeramounts of conveying liquid can flow through the pipe 32 into the pumphousing. The liquid enters the hollow space 57 on the inlet low-pressureside of the control element 36; this hollow space is hydraulicallyconnected through openings 58 of the control element, with the ho]- lowspace 59 on the inlet side of the pump impeller 19. From there, theliquid is forced into the hollow space 60 on the outlet high-pressureside of the impeller 19 and leaves the pump housing through the now openbore of the connecting pipe 33. By turning the control element 36 by180, the conveying direction of the pump can be reversed in a simplemanner, the connecting pipes 32, 33 reversing their respectivefunctions.

In order to cool, during operation, the radial bearing formed by theaxle 15 and the shaft box 16, and in order to lubricate same withconveying liquid, the shaft box 16 is provided with lubricating grooveswhich are not shown, and which run in the axial direction. Theselubrieating grooves are hydraulically connected, via radial channels 61of the motor rotor 17, 18, with the high pressure chamber 60. Uponrotation of the rotor, conveying liquid is constantly fed to thelubricating grooves. At

the same time, the conical bearing 22, 23 is lubricated by an axial bore62 of the impeller boss 21. An annular protective shell 70 located onthe membrane 8 prevents the flushing of larger particles of dirt intothe channels 61, the motor air gap, and the bearing slots.

When the pump impeller 19 adheres tightly to the axle 15, for example,after a longer operating pause, and can not be detached by the startingtorque of the axial motor, the control element 36 is placed in itsclosed position. If then the locking screw 45 is removed, a screw drivercan be inserted through the aligned central bores of the hand-l wheel 39and the hub 35 of the control element 36, and can be brought intoengagement with the groove 63 on the free front side of the boss 21 ofthe pump impeller 19, in order to free the pump impeller by hand.

When the air gap of the motor and the bearing surfaces are to becleaned, or other parts of the assembly are to be checked or replaced,the pump housing 1 is again blocked against the liquid cycle with theaid of the control element 36. Then, the screws 26 are loosened, wherebythe motor block housing 2, along with the unit formed by the motor rotor17, 18 and the pump impeller 19, can be removed. The motor rotor and thepump impeller can be pulled off the axle 15 with one grip.

The embodiment of the invention illustrated in FIG- URES 5 and 6 differsfrom the previously described embodiment only in that measures areprovided for deblocking the assembly. For this purpose, the controlelement 36 is mounted, with its boss 35 in the front wall 34 of the pumphousing 1, against the force of the cup springs 49, in an axiallydisplaceable manner. A tappetfollower 68 with a tappet nose 69 isfixedly inserted in the front face of the box 35 facing the pumpimpeller 19. The opposite front face of the boss 21 of the pump impeller19 is provided with a groove 67 suitable for receiving the tappet nose69.

In order to de-block the pump impeller 19, the control element 36 isdisplaced axially toward the inside by means of pressure exerted uponthe handwheel, and, if required, rotated at the same time until thetappet nose 69 engages the groove 67. By subsequently turning thehandwheel 69 even further, the blocked pump impeller is loosened.

Thus, the motor rotor is provided advantageously with radial channelswhich are in communication with, on the one hand, the bearing slot spaceon the low-pressure side and, on the other hand, the outer rotor spaceon the highpressure side. Through the radial channels, with the rotorrotating, a flow of liquid is constantly maintained which cools andlubricates the bearings of the unit formed by the motor rotor and thepump impeller.

By actuating a single component partthe control element-flow of theconveying liquid through the inlet and outlet openings can be throttled.By fashioning the outer surface of the control element, which sealinglyengages, in the closed position of the control element, the liquid inletand outlet openings, to be cylindrical, it is avoided that a fluidpressure which might be ambient in the pump inlet line exerts an axialimpetus upon the control element which was placed in its closedposition, which axial impetus can lead to undesired problems in themounting and sealing of the assembly. Moreover, because of the use of anaxial motor, a conveying assembly can be provided having a totalrelatively short axial structural length not considering the axial spacerequired for the control element.

The radial inlet and outlet openings of the pump housing are preferablypositioned diametrically opposite to one another, so that the directionof flow of the conveying liquid through the pump can be reversed byturning the control element by The pump housing can be provided, for thefeeding and discharging of liquid, with several openings, for example,two inlets and one common outlet, which all cooperate with the controlelement. In this manner, the conventional mixing effects for severalconveying liquid cycles can be obtained.

In a further development of the invention described above, the unitformed by motor rotor and pump impeller is furthermore mounted on afixed axle connected with the motor block housing and is rotatable; thisfixed axle, in addition to being a radial mounting, forms a conicalbearing serving as the axial bearing for the unit consisting of motorrotor and pump impeller. A further radial bearing is not necessary. Theconical bearing keeps the frictional forces small which must be overcomeby the motor. This fact ensures, in conjunction with the fact that themotor block, according to the invention, can be easily disassembled andcleaned, the use of a relatively weak, low-noise, inexpensive motor,even when conveying polluted liquids; the starting torque of this motorwhich is actually weak, particularly in case of one-phase alternatingcurrent supply, is still suflicient to ensure safety in operation.Furthermore, after the housing has been opened and the motor block hasbeen lifted off, the unit formed by the motor rotor and the pumpimpeller can be removed from the axle with one reach, and withoutrequiring the loosening of further screws or other fastening means, inorder to visually examine the slot between the motor stator and rotor tofind any disturbing foreign bodies present therein, and to remove theseforeign bodies, if necessary. When reassembling the assembly, notime-consuming and cumbersome adjustment procedure need to be conducted.

As shown, the pump housing can be provided advantageously with anopening which is normally closed, through which opening the pumpimpeller can be manually rotated from the outside. This constructionmakes it possible to free the pump in a simple manner, for ex ample,when the pump is blocked after rather long periods of inoperativenessbecause of calcium deposits from the conveying liquid or the like, sothat the starting torque of the motor is insuflicient to initiate theoperation of the pump. The control element need only be placed in theclosed position in order to separate the pump housing from the fluidcycle. Then, the opening of the pump housing which is normally sealed ina fluid-tight manner by a locking screw, for example, can be opened anda tool, for example, a screw driver, can be inserted through thisopening with whose aid the unit formed by the pump impeller and themotor rotor is forcibly turned by hand. This measure can make thedisassembly of the motor block superfluous, particularly when the degreeof blockage by foreign bodies is rather slight.

Aocording to a modified embodiment of the invention shown, an even moreconvenient possibility to free the pump is created by making the controlelement not only rotatable, but additionally externally axiallydisplaceable and connectible with the pump impeller. If the pump isblocked, the control element need only be coupled with the pumpimpeller, and then the impeller can be freed by turning the controlelement. The coupling between the control element and the pump impellercan be flush or frictional coupling. A frictional coupling makes itpossible to check the direction of rotation of the rotor when the motoris running.

The conveying efficiency of the pump can be improved, as has beendiscovered, with the other conditions remaining the same, by delimitingthe liquid inlet opening in the outer surface of the control element inthe eifective area of the egress of the impeller by means of guideflanks forming an acute angle with the tangent on the circumference ofthe control element, and whose outer peripheral spacing is approximatelyequal to the length of the periphery of the liquid inlet opening of thepump housing.

In order to make it possible to conduct a fine adjustment of theconveying volume of the pump, the liquid inlet opening in the outersurface of the control element is preferably provided with across-sectional aperture area which varies in the direction of thecircumference. The change in cross section can be continuous, or in oneor several steps.

The stator of the axial motor provided in the motor block housing is, ina further embodiment of the invention, separated from the rotor by afluid-tight membrane positioned in the dividing plane of the housing. Inthis manner, the stator carrying the windings through which current isflowing is protected from moisture in a simple manner. Since themembrane is positioned in the air gap of the motor, and this air gap isnot to exceed a relatively small maximum value, the thickness of themembrane is limited. In order still to obtain a high mechanical strengthand to avoid damage to the membrane by higher fluid pressures whichmight occur in the pump housing, the membrane is suitably supported onthe stator side by an insulating layer, for example, a synthetic resinmass, filling the adjacent space of the stator windings.

It should be understood, of course, that the foregoing disclosurerelates to only preferred embodiments of the invention and that it isintended to cover all changes and modifications of the examples of theinvention therein chosen for the purposes of the disclosure, which donot constitute departures from the spirit and scope of the invention setforth in the appended claims.

What is claimed is:

1. A controllable liquid conveying assembly for feeding and radiallydischarging liquid, devoid of stuffing boxes and glands, comprising: acommon housing axially divisible into a pump housing (1) and a motorblock housing; said pump housing having liquid inlet and outlet openings(32, 33); a control element adjustable externally of the housings forcontrolling the feeding and discharge of the liquid; the control element(36) provided with sealing elements (50, 51, 52) permitting afluid-tight sealing of the inlet and outlet openings (32, 33) of thepump housing (1); a pump impeller; and an axial motor having a rotoroperatively connected therein; said motor being mounted in said motorblock housing and having a pump-motor shaft axis (15), said motordriving said pump impeller.

2. Liquid conveying assembly accordingly to claim 1, the control element(36) situated coaxially to the pumpmotor axis, and provided with acylindrical outer surface (48) movable to seal the liquid inlet andoutlet openings.

3. Liquid conveying assembly according to claim 1, the liquid inlet andoutlet openings of the pump housing facing one another diametrically,and means to reverse the direction of flow of the conveying liquidthrough the pump by turning the control element by 4. Liquid conveyingassembly according to claim 3, the pump housing provided with severalopenings for feeding and withdrawing the liquid, to cooperate with thecontrol element.

5. Liquid conveying assembly according to claim 1, the motor rotor andthe pump impeller forming a unit rotatably and removably mounted on afixed axle con nected with the motor block housing.

6. Liquid conveying assembly according to claim 5, a conical bearingprovided as the axial bearing for the unit formed by the motor rotor andthe pump impeller.

7. Liquid conveying assembly according to claim 1, the pump housingprovided with a normally closed opening, permitting turning of the pumpimpeller therethrough by hand from the outside.

3. Liquid conveying assembly according to claim 1, the control elementaxially displaceable from the outside within predetermined limits, andconnectible with the pump impeller.

9. Liquid conveying assembly according to claim 3, said outer surface(48) of the control element having a liquid inlet opening delimited inthe eifective range of the egress of the impeller by guide flanks (54,55) which form an acute angle with the tangent on the circumference ofthe control element, and which have an outer peripheral spacingapproximately equal to the peripheral length of the liquid inlet openingof the pump housing.

10. Liquid conveying assembly according to claim 3, the liquid inletopening in the outer surface of the control element having across-sectional area of its aperture, changeable in the direction of itscircumference.

11. Liquid conveying assembly according to claim 1, the stator of theaxial motor, provided in the motor block housing separated from themotor rotor by a fluid-tight membrane located in the dividing plane ofthe housing.

12. Liquid conveying assembly according to claim 11, a stator Windingchamber, the membrane on the side of the stator supported by aninsulating layer filling the neighboring stator winding chamber.

13. Liquid conveying assembly according to claim 1, further comprising alow-pressure side bearing slot cham- References Cited UNITED STATESPATENTS 2,752,857 7/1956 White 103-87 2,846,951 8/1958 Metral et a1.1()387 3,183,837 5/1965 Helliwell 103-97 X 3,194,165 7/1965 Sorlin103-87 3,289,597 12/1966 Stehrenberger et al. 103-97 ROBERT M. WALKER,Primary Examiner.

